Warning siren



FIG. 1 is a perspective side view of a warning siren showing my new design;

FIG. 2 is a right side elevational view thereof with the left side being a mirror image thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof.

The broken line showing of mounting holes is included for the purpose of illustrating portions of the “article” and forms no part of the claimed design. 

CLAIM The ornamental design for a warning siren, as shown and described. 